WAQS Source Apportionment Modeling Update - PowerPoint Presentation

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WAQS Source Apportionment Modeling Update

Ralph MorrisIWDW/WAQS Technical CommitteeJanuary 12, 2016Fort Collins, Colorado

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Content: Source Apportionment (SA)

Overview of WAQS Source Apportionment PlanRound 1 – Geographic (done)Round 2 – Source Sector (done)Web-based SA Visualization Tool (in progress)Round 3 – Detailed 4 km SA (not started)

Preliminary Results (Round 1)

Visualization Tool Status (Update)

Updates to CAMx SA Tool (information)

Potential Approaches for Round 3 (feedback)Slide3

R1: Geographic Source Apportionment

2011a Emissions

21 Source Regions

5 Source Categories

Natural (Bio, Lx, SS, WBD)

3 Fires (WF, Rx, Ag)

Remainder AnthropogenicOzone/APCA 36/12 kmPSAT/PM 36 km O3, PM, Vis and Dep ContributionCSAPR-type AnalysisRHR Impaired vs. W20% DaysSlide4

R2: Source Sector Apportionment

2011b EmissionsSource Categories:Natural (Bio,

LNOx

, SS, WBD)

Wildfires (WF)

Rx+Ag Fires

O&GEGU PointOther PointOn-RoadNon-RoadRemainder AnthroFive Source RegionsCO, UT, WY and NMRemainderSlide5

R3: Detailed 4 km SA

Examine local source contributions in more detail, possibilities: Episodic period(s) from 2011State subregionsSource subcategoriesWill discuss in more detail at end of this PPTRequest feedback from Technical Committee

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R1 Results: CASPR-Type Analysis

Run Model Attainment Test Software (MATS) using CAMx base output and output from each State’s anthropogenic emissions removedAnthro = Anthropogenic + Rx and Ag firesProvides State’s contribution to Design Values8-Hour Ozone and 24-Hour and Annual PM2.5 CASPR-type analysis

User selects level of NAAQS and Upwind State

Spread sheet performs analysis summarizing Downwind States where the Upwind State contributes significantly

Significance defined as 1% of the NAAQS

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Drop Down Menu for Upwind State and Level of NAAQS Slide8

Downwind States where the Upwind State (CO) Contributes Significantly to Ozone Nonattainment in a Downwind State under 70 ppb Ozone NAAQS

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Source Contributions at Downwind States

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Web-Based SA Visualization Tool

Received comments on Prototype that was based on 2008 WestJumpAQMS top highest modeled 8-hour ozone daysBiggest comment was to extract SA information at more locations than just the monitoring networksAdded virtual gridded network covering western U.S. at 36 km resolutionUpdated SA Vis Tool with WAQS R1 Geographic ozone SA results for every day of year

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WAQS Receptors

for Data Extraction11

Ozone

PMSlide12

Ozone Vis Tool Opening PageSlide13

Site Selection: Dropdown or MapDay Selection: Dropdown or Calendar

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AQS Network Locations

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Map Browser

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Day Selection

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Add Time Series SA CapabilitySlide18

Updates to CAMx Source Apportionment Tool

OSAT – apportion ozone changes (ΔO3) to tracers O3N and O3VAPCA – only assign O3 formed to biogenic when due to

interactions

of biogenic VOC and biogenic NO

X

(policy relevant)

“OSAT2” – simultaneously treat O3 production and destruction“OSAT3” – treat odd oxygen in NO2 and NOX recycling Slide19

Improve OSAT algorithms

Track odd-oxygen through NO

2

When NO

2

accumulates, e.g., overnight in urban cores

Requires NO2 apportionmentTrack NOX recyclingSource of NOX where emissions are lowApportion HNO3 (etc.) which PSAT does

Must apportion

O

and

N

in NO

2

independently

Odd-oxygen in NO

2

(ONO)

Follow the

O

:

NO +

O

OO



O

NO

O

NO + hv  NO +

O

O

+ OO 

O

OO

NO

X

recycling

Follow the

N

:

OH +

N

O

2

 H

N

O

3

H

N

O

3

+ hv  OH +

N

O

2

also for PAN and nitrates

Purpose of OSAT Update

Content slideSlide20

OSAT (1995-2004)

OSAT uses 4 Reactive Tracers for each Source Group:Ni -- Nitric oxide (NO) and nitrogen dioxide (NO2) emitted by source group i

V

i

-- VOC

emitted by source group iO3Ni -- O3 formed under NOX-limited conditions from NiO3Vi -- O3 formed under VOC-limited conditions from ViNOX- vs. VOC-limited determined by ratio of instantaneous production of hydrogen peroxide and nitric acid[PH2O2]/[PHNO3] < 0.35  NOX-limited (Sillman, 1995)When total change in ozone (ΔO3) is positive, allocate Δ

O3 to Source Groups based on contribution of limiting precursor (N or V)

When

Δ

O3 is negative, detriment Source Groups O3N and O3V equally on total percentage basis

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OSAT2 (2005-2015)

OSAT2 recognizes that ozone formation and destruction can occur at the same timeCalculate ozone destruction (DΔO3) due to reactions:

O

3

+ VOC reactions since these remove ozone;

O(

3P) + VOC reactions since these effectively remove ozone;O(1D) + H2O reaction since this effectively removes ozone;HOX + O3 reactions that do not re-form ozone.Ozone formed PΔO3 = [ΔO3 – DΔO3]Allocate PΔO3 and DΔO3 to Source Group reactive tracers using same reactive tracers and rules as OSATSlide22

OSAT3 (2015+)

Track odd oxygen and nitrogen recyclingNeed many more (10) reactive tracers than OSAT/OSAT2 (4):Vi VOC emitted by source group iNIT

i

Nitric oxide (NO) and nitrous acid (HONO)

RGN

i

Nitrogen dioxide, nitrate radical (NO3) and dinitrogen pentoxide (N2O5)TPNi Peroxyl acetyl nitrate (PAN), analogues of PAN and peroxy nitric acid (PNA)NTRi Organic nitrates (RNO3)HN3i Gaseous nitric acid (HNO3)O3Ni O3 formed under NOX-limited conditions from NiO3Vi O3 formed under VOC-limited conditions from ViOONi Odd-oxygen in NO2 formed from O3NiOOVi Odd-oxygen in NO2 formed from O3ViAlso update PSAT with more tracers to be consistent with OSAT3Slide23

OSAT2 vs. OSAT 3 ComparisonSlide24

OSAT2 vs. OSAT 3 Comparison of

Local Contributions24Slide25

Updates to Ozone Source Apportionment

OSAT3 completed and operationalApportions odd-oxygen in NO2Tracks NOX-recyclingOSAT3 uses more tracers

Larger output, slower runs

Contributions change

Generally smaller local contribution

Generally larger transported

contributionNO2 explicitly tracked as own tracer speciesCan now do explicit contributions for 1-hour NO2 assessments instead of using RGN speciesPSAT also updatedN tracking compatible with OSAT3Publicly released with next version of CAMx (V6.3?) in 201625Slide26

2011 Detailed 4 km Apportionment

SA Plan presents several possibilities:Summer ozone SA with more geographic subregions and source subcategories

Winter ozone period

PM2.5 or visibility events

New ideas:

OSAT3/PSAT3

Other???Limited by available resources